Revolving cement mixer screen



Jan, 3 E, 1950 A. WEHNER ZAQWUF'ZY REVOLVING CEMENT MIXER SCREEN Filefi Feb. 10, 1947 2 Sheets-Sheet l Albert Wehner Jamo 31, 395E A; WEHNER ZAQ6JU 'Y? REVOLVING CEMENT MIXER SCREEN Filed Feb. 10, 1947 2 Sheets-Sheet 2 "1i"? 'iii'iiiiir Alberf Wehner 3 Attorneys Patented Jan. 31, 1950 UNITED STATES harem" OFFICE REVOLVING CEMENT MIXER SCREEN Albert Wehner, Harbor Beach, Mich. Application February 10, 1947-, SerialNo. 727,633

Claims. (01. 259*145) This invention appertains to. new and useful improvements in sifting screens particularly adapted to be used in making concrete and the like.

An object of thisinvention istoprovide a labor and time saving device for screening an aggregate prior to entry into the conventional rotary mixing chamber element of a concrete preparing machine. 7 I

Another object of this'invention is to provide means for securing the sifting element tosaid rotary mixing element. 2

Another object-of: this invention is to provide means for selectively opening and closing the aperture in the conventional cement mixing rotary chamber member.

A further object of this invention is to provide a latching means to be used in conjunction with the above mentioned means.

A still further object of this invention is to provide a device which is extremely simple, requiring but a very few parts for fabrication.

Ancillary objects and features of novelty as well as those specifically set forth hereinabove will become apparent to those skilled in the art, in following the description of the illustrated preferred embodiment of the present invention, illustrated in the accompanying drawing, wherein:

Figure 1 is an elevational side view of a convent onal rotary cement mixing chamber with the invention secured thereto;

Figure 2 is an end view of the invention disclosed in Figure 1;

Figure 3 is an elevational side view of the invention disclosed in Figure 1 with parts broken away, showing details of construction; and

Figure 4 is a transverse sectional view of the invention disclosed in Figure 2 and taken substantially on the line 4-4 thereof and in the direction of the arrows.

It is the present practice of cement workers, using the conventional rotary chamber mixing machine, to screen the usual aggregate by the use of a leaning, stationary screen. This invention has been devised to obviate the necessity of this screening, thereby avoiding a complete step in making or mixing the components of concrete.

A conventional rotary cement mixer element It is provided with the usual opening or aperture I2 at one end thereof. A collar is is composed of some suitable material, preferably metallic, and is adapted to encircle the rotary mixing chamber adjacent the said aperture [2. This member Hi is a collar adapted to be complemental to the surface exterior of said. member. It, and since it. is conventional to use an annular shaped rotary mixing element, the preferred. configure. tion of the said collar M is annular. A pair of shafts l6 and i8 project through said collar and are provided with ri ht angular extensions 201' and 22, respectively, which are adapted to be used as handles and latching means. A pair of clips 24 and. 26, respectively, are. rigidly secured to the said collar l4, exterior thereof. Any suitable se curing means may be used for this purpose, such as the rivets. 28 shown in Figure 3. It is rather apparent from an inspection of Figures 2 and 3 that the said handles 22 are adapted to be clipped in said securing means or friction clips, in a certain predetermined position. of. said shafts.

A pair of substantially semi-circular sieve members 30 and 32, respectively, are secured to said shafts at the straight edge of said sieve members. The said sieve members are provided with a plurality of apertures 34 of selected predetermined size, which size is determined by the quality of concrete which is to be made. It can now be seen that upon actuation of the handles 22 and 24 the screens 30 and 32 may be opened or closed, that is, open to a position as shown in Figure 3, or closed to the cement mixing element aperture closing position.

About the periphery of the said collar I4 is a plurality of apertures 36 adapted to receive friction securing means therein. The preferred form of friction securing means is the simple set screw 38, disclosed in the drawings. This form of securing means was chosen in order that the collar may be easily and conveniently removed from the said mixing element 10.

In operation, aggregate is piled on the screening elements 39 and 32 while said elements are in the latched position. If so desired, the mixing elements It may be rotated, thereby sifting said aggregate into the mixing chamber. Of course, the undesirable portions of the aggregate will simply be thrown out. In pouring the concrete, the usual cement mixing machine adjustment may be used to tilt the rotary chamber while gravity opens the said screen. If gravity isnt sufficient, the handles 20 and 22 may be pulled slightly to release the latches 24 and 26.

Due to the extreme simplicity characterizing this invention, a further description thereof is deemed unnecessary. However, protection is sought on all the modifications falling in the purview of this invention, and therefor limitation is sought only in accordance with the scope .of the following claims.

What I claim is:

1. An aggregate sifting closure for a rotary mixing chamber comprising an annular collar, shafts projecting therethrough, latch rods on said shafts, latch keepers secured exterior of said collar adjacent said latch rods, screens secured to said shafts adapted to selectively open and close the bore of said collar, adjustable securing means secured to said collar for attachin said hopper to a cement mixing rotary chamber.

2. In a cement mixing machine, a cement mixing rotary chamber member, an annular collar, shafts projecting therethrough and having latch rods at the ends thereof, latch keepers secured to the exterior surface of said collar adjacent said latch rods to releasably hold said latch rods, screens secured to said shafts adapted to selectively open and close the bore of said collar, adjustable securing means carried by said collar for attaching said collar to a cement mixing ro-v tary chamber member.

3. An aggregate siftin device including a collar, means carried by and extending through said collar for securing said collar to a cement mixing rotary chamber member, shafts projecting through said collar, means for locking said shafts in a predetermined position, sifting means fixed on said shafts, said locking means comprising friction clamps secured to the exterior surface of said collar.

4. An aggregate sifting device including a collar, means carried by and extending through said collar for securing said collar to a cement mixing rotary chamber member, shafts projecting through said collar, means on said collar for locking said shafts in a predetermined position,

sifting means on said shafts, handles associated with said shafts, said locking means including clips on said collar lockingly engaging said handles, said securing means including a plurality of set screws.

5. An aggregate sifting device including a collar, a plurality of set screws extending through said collar for securing said collar to a cement mixing rotary chamber member, shafts project- REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,106,022 Adams Aug. 4, 1914 1,185,255 Smith May 30, 1916 1,231,694 Becker July 3, 1917 1,402,520 Mendel Jan, 3, 1922 1,460,571 Carey July 3, 1923 FOREIGN PATENTS Number Country Date 15,098 Great Britain Aug. 10, 1895 

